Electrical heater



Aug. 11, 1931. y

o. D. rHoRsNEss ET AL ELECTRICAL HEATER Filed Feb. 1 9, 1929 Patented Aug. 11, 1931` UNITED STATES PATENT orifice or'ro n. 'IHonsNEss .um nEwEYn 'rowma` o Igaxj mansion. sourir nanou, sIGNoas To ELEc'rnIc HEATING DEVICES, nrc., or Lm rnasrox, sown nuora,

A CORPORATION OF SOUTH DAKOTA ELECTRICAL HEATER application mea rem-nary 19, 1929. serial no. 341,11?, f

This invention relates to electrical heaters, and more particularly to heaters for insertion in the water circulation systems of automobile engines for heating the water of f the system during extremely cold weather to thereby facilitate starting of the car or to prevent freezing of the water in the system durin periods when the engine is idle.

An lmportant object of the invention 1s to produce a device of this character which will be highly efficient in 'operation and which, at the same time, may be very readily and cheaply manufactured and may be very readily installed in the engine.

A further object of the invention is to provide a construction such that a maximum transfer of heat from the heating coil to the water system is obtained. y

These and other objects we attain by the ze construction shown in the accompanying drawings, wherein for the purpose of illus'- tration is shown a preferred embodiment of our invention and wherein Figure 1 is a plan view of a heating element constructed in accordance with our inyvcfention;

I Figure 2 is a section on the line 2-2 of Figure 1.

Figure 3 is a section on the line 3-3 of Figure 1. f

Referring now more particularly to the drawin the numeral 10 indicates a tube, the en s of which are slightly tapered in exterior diameter, as indicated more clearly at 11, so that they may be readily inserted in the flexible hose connection 12 commonly employed for connecting the radiators and engines of internal combustion en ines. This tube has a central portion thereo provided with inwardly extending longitudinally ydirected ribs 13. About this central rtion of the tube is placed a layer of thin exible insulating material, such as mica, as indicated at 14, upon which is wound a heating coil 15. The mica and heating coilvare anchored in position by means of asbestos or other insulating cement 16 which is placed over the coil and mica in a thin layer which engages at its ends with the tube and seals thereto so that there is no possibility for escape of the coil. I.

Upon thetube at opposite ends thereof are placed collars 17, each having an inwardly directed. peripheral Ifiange y 18. v A cylindrical wall easing 19 is provided', this casing being of considerably greater diameter than the outside of the cement layer, so that a space 20'isformed therebetween. One end of this cylindrical wall is formed .with a notch! 21 recei' an insulating block of some heat resista insuiating material, such as slate, porceiain or thelik'e.

The side and end walls of the block are grooved, as at:V 22,sothat this block may be slid into the groove but when in position, may not miov'e transversely of the housing.

rThe Hnge vthis end of the housing is likewise notched, as indicated at 23, to receive the block. This block mounts binding posts 24 to which the ends of the heating coil are electricallyl connected. The space 2O is filled with some cellular heat and electrical insulating material, such asasbestos, which serves at once to prevent the escape of heat generated in the coil through the casin walls and to prevent electrical contact o the lead wires with the walls of f the casing. I

It will be obvious that a device of this character may be very readily and cheaply constructed and may be very readily inserted in the water circulation system of the automobile. It will also be obvious that the construction hereinbefore set forth is capable of a certain range of change and modification without materially departing from the spirit of the invention and we accordingly do not limit ourselves to such specific structure except as hereinafter claimed.

We claim f I 1. In a. heater of the type described, a metallic tube having tapering opposite end portions whereby to permit mounting of the tube in a flexible conduit, an electrical heating element surrounding the tube and secured against shiftin movement thereon, a casing surrounding t e tube and sealed at its ends thereto, said casing having the walls thereof in spaced relation to the electrical 100 'roA heating element and having the opposite ends thereof spaced inwardly of the opposite ends of the tube, and a filling of heat and electrical insulating Within the casing about the heating element, the inner Wall of said tube having inwardly projecting radiation ribs.

2. In a heater of the type described, a metallic tube having tapering opposite end port-ions whereby to permit mounting of the tube in a flexible conduit, an electrical heating element surrounding the tube and secured against shifting movement thereon, a casing surrounding the tube and sealed at its ends thereto, said casing having the Walls thereof in spaced relation to the electrical heating element and having the opposite ends thereof spaced inwardly of the opposite ends of the tube, a filling of heat and electrical insulating Within the casing about the heating element, said heating element comprising an inner layer of flexible insulating material directly engaging the tube, a. coil wound upon said insulating material, and a layer of insulating cement covering the insulating material and coil and engaging with the Wall of the tube at its ends, the inner Wall of said tube having inwardly projecting radiation ribs.

In testimony whereof We hereunto ailix our signatures.

OTTO D. THORSNESS. DEVEY R. TOVER. 

